Card-matching numbers (Dinner-Diner matching numbers) for 5 kinds of cards.

Terms

a(0) =1a(1) =44a(2) =45a(3) =20a(4) =10a(5) =0a(6) =1a(7) =440192a(8) =975360a(9) =1035680a(10) =696320a(11) =329600a(12) =114176a(13) =31040a(14) =5120a(15) =1280a(16) =0a(17) =32a(18) =52097831424a(19) =179811290880a(20) =298276007040a(21) =315423836640a(22) =237742646400a(23) =135296008128a(24) =60059024640